Venomous snake found on naturally snake-free island in Germany for first time. See it
On a naturally snake-free island in northern Germany, rumors of snake sightings have swirled for decades, but scientists never took them seriously — until now. One resident’s chance encounter and photograph to prove it changed that.
A resident of Sylt Island noticed a snake on a village street in May, snapped a photograph of it and uploaded it to the citizen-science project Beach Explorer, scientist Harald Ahnelt wrote in a study published March 14 in the peer-reviewed journal Check List.
At first glance, the photo looks slightly grainy and relatively mundane, but it quickly caught Ahnelt’s attention.
Sylt Island, located in the North Sea near the Germany-Denmark border, is part of an island chain “naturally void of snakes,” he wrote. But, since the 1970s, islanders have occasionally reported snake sightings. These “oral reports” were generally considered “doubtful or questionable” by scientists.
The 2024 photo, however, clearly showed a Vipera berus, also known as the common European adder or common European viper, on Sylt Island, the study said. It was the island’s first confirmed sighting of the venomous species and “the northernmost record in Germany.”
But how did the viper get there?
Common European adders are native to and “widely distributed” on the nearby mainland of Germany and Denmark, and the species is “known to be able to cross marine waters,” Ahnelt said. The island also had several confirmed sightings of a non-venomous snake species accidentally imported “with construction material.”
Similarly, the common European adder could have “arrived recently with transported material,” or it could have been an escaped or released pet, the study said. Information on the sighting is slim, and its origin is a mystery.
In Germany, common European adders are considered “critically endangered,” the study said.
The species is one of the country’s only venomous snakes and “thrives in colder climates,” according to a 2023 article from the German newspaper Deutsche Welle. “While adder bites can be painful and cause swelling, they are very rarely dangerous for humans.”
This story was originally published March 21, 2025 at 8:45 AM with the headline "Venomous snake found on naturally snake-free island in Germany for first time. See it."
